Question

为什么这句话中有两个动词?1.He has written a letter.2.He had written a le

Answer 1

has,had,will have & had been 都不要理解为动词,它们都只是用于表示事态.

1里,动词是write,has + 过去分词,现在完成时的用法

2里,动词是write,had + 过去分词,过去完成时的.

3里,主句里动词是write,从句（before I come）修饰时间,动词是come; will have + 过去分词,将来完成时的用法.

4里,主句动词是write,从句也是修饰时间,动词是come,had been doing sth,是过去完成进行时.

希望没解释错,N年前学的了.记住几个事态的用法,造句时套上不同的动词就可以了.